Tianjin (; Postal map spelling: Tientsin) is a metropolis in northern China and one of the five national central cities of the People's Republic of China (PRC). It is governed as one of the four direct-controlled municipalities of the PRC, and is thus under direct administration of the central government. Tianjin borders Hebei Province and Beijing Municipality, bounded to the east by the Bohai Gulf portion of the Yellow Sea. Part of the Bohai Economic Rim, it is the largest coastal city in northern China. - Source: Wikipedia